In a dramatic dawn raid yesterday, cops swooped down on a Brooklyn apartment and nabbed a key figure in an international plot to sow terror by bombing millennium celebrations, authorities said.

The raid netted four Algerian immigrants – one of whom feds said had direct connections with the Algerian terrorist caught delivering a cache of deadly explosives to Seattle Dec. 14.

Abdel Ghani, 31, who had spent time in Afghanistan, was in Seattle Dec. 11 to Dec. 16, allegedly to meet his compatriot in terror.

But he was unable to connect with Ahmed Ressam because Ressam was arrested trying to smuggle the explosives into the United States from Canada, officials said.

Ressam’s arrest sparked fears that terrorists were planning to bomb millennium celebrations. A Manhattan federal court complaint reveals the extent of those plans.

In the complaint, Ghani said Ressam was part of a “well-organized group” that ordered the Algerian terrorist to deliver a rental car loaded with the explosives to a parking lot in Seattle.

The keys were to be left in the car and another group member was to retrieve it.

The complaint does not spell out the target, but quotes Ghani as saying that “Allah will shake up this world, that a new generation will punish America and that Islam’s renaissance will rise from Algeria.”

After dropping off the car, Ghani and Ressam were to travel to Chicago and other places to raise money for the group, authorities said.

But the alleged plan went awry when Ressam was arrested in Port Angeles, Wash., after arriving on a ferry from Vancouver.

When cops searched him, they found a piece of paper with the name Ghani on it and a phone number with a 718 area code, officials said.

That led investigators to Ghani, who returned to Brooklyn and tried to destroy evidence of his trip to Seattle, which included an airline ticket and a bank statement, according to the complaint.

Both items were in the name of Eduardo Rocha, an alias he used, authorities said.

Ressam was charged with trying to smuggle RDX, the basic component of plastic explosives, other explosives and timing devices into the country.

Ghani was charged with concealing material support for Ressam, a charge that carries a maximum penalty of 10 years.

He was arrested by a task force of 150 cops and FBI agents that raided a second-floor apartment in a modest three-story home in the Midwood section.

Three other men were taken into custody. Two were released, but a third, Najmeddin Houaichi, 35, was held.

No explosives were found.

Mayor Giuliani said the raid – a day before New Year’s Eve- “does not involve any specific threat involving New York City.”

“The reality is that this does not involve any information regarding a specific plan or plot directed toward the City of New York.” he said. “We’ve known about it for some time.”

Ressam has also been linked to Lucia Garofalo of Montreal, who was arrested Dec. 19 while trying to cross the border in Vermont with an Algerian man accused of using a false passport.

At a bail hearing in Burlington. Vt., yesterday, prosecutors said Garofalo and Ressam were members of the same cell of the Armed Islamic Group, known by its initials GIA in French.

The GIA is a fundamentalist group responsible for some of the bloodiest attacks during Algeria’s eight-year civil war.